Text and, to a lesser degree, speech chatting systems, are generally known in the art, particularly in relation to personal computing systems. Published U.S. patent application Ser. Nos. 2001/0042095 A1; 2001/0011293 A1; and 2002/0023128 A1 and U.S. Pat. Nos. 6,212,548 and 6,286,034 illustrate exemplary system and user interfaces used today. A common feature of such systems is that the various conversations (or threads) are usually split out into distinct regions (or windows) on the display or screen. Furthermore, when a single thread comprises a plurality of both text and speech exchanges, such systems usually separate the two modalities. The speech is usually played over a speaker, whereas the plurality of text messages are displayed on the screen. Users have no means to reference old speech messages or distinguish when they occurred in the thread relative to other messages in that thread.
Particularly troublesome is the fact that such interfaces become unwieldy when implemented on small screen devices with cumbersome text input mechanisms (as is common on mobile terminals in today's wireless markets.)
Published U.S. patent application Ser. No. 2002/0023128 A1 (“the '128 Publication”) describes a system where the screen area is split into six distinct windows. One window presents a chat history of one thread (the thread in focus) while another window displays a chat history of the combined plurality of the remaining threads. A chat history comprises a plurality of entries displayed on the screen that describe both inbound (i.e., received by the user's mobile terminal) and outbound (i.e., sent by the user's mobile terminal) chat messages. The entries are usually displayed on the screen in chronological order and usually only describe text messages.
The '128 Publication also exemplifies the verboseness of chat history entries displayed on the screen. An entry might list a timestamp, a thread identifier, the sender's identifier, and the message. In the case that a single message targets a plurality of individuals (i.e., a chat group), the entries may contain a list of the plurality of other recipient's information as well. The combined information of all the entries in the chat history is too overwhelming for very small displays.
Therefore, it would be advantageous to provide a technique for displaying multiple chat threads (or histories) using limited display areas. Such a technique should accommodate the occurrence of speech messages, and should avoid the verbosity of prior art techniques.